3791. Ethylene

Nomenclature

CAS number: 74-85-1
Ethene; elayl; olefiant gas.
C2H4; mol wt 28.05.
C 85.64%, H 14.37%.
CH2=CH2.

Description and references

Plant hormone; occurs in ripening fruit, in illuminating gas (up to 4%). Prepd by decompn of petr gases or by dehydration of alcohol. Lab prepn from alc: Gattermann-Wieland, Praxis des Organischen Chemikers (de Gruyter, Berlin, 40th ed, 1961) p 98; F. A. Wunder, E. I. Leupold, Angew. Chem. Int. Ed. 19, 126 (1980). Biosynthesis from 1-aminocyclopropane-1-carboxylic acid: D. Adams, S. F. Yang, Proc. Natl. Acad. Sci. USA 76, 170 (1979). Proposed mechanism of biosynthesis: M. C. Pirrung, J. Am. Chem. Soc. 105, 7207 (1983). Toxicity data: Flury, Arch. Exp. Pathol. Pharmakol. 138, 65 (1928). Comprehensive monograph: S. A. Miller, Ethylene and its Industrial Derivatives (Ernest Benn Ltd., London, 1969) 1321 pp. Review of ethylene in biological systems: Spencer, Fortschr. Chem. Org. Naturst. 27, 31-80 (1969); of manuf: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 376-384; of carcinogenic risk: IARC Monographs 60, 45-71 (1994). Review: K. M. Sundaram et al., in Kirk-Othmer Encyclopedia of Chemical Technology vol. 9 (Wiley-Interscience, New York, 4th ed., 1994) pp 877-915.

Properties

Colorless gas with faint sweet odor. Burns with a luminous flame. Solidif -181° forming monoclinic prisms. mp -169.4°, bp700 -102.4°. Vapor density 0.978 (air = 1.00). One liter of ethylene gas at 760 mm and 0° weighs 1.260 g. bp2 atm -90.8°; bp10 atm -52.8°; bp30 atm -14.2°; bp50 atm 8.9°. d46.5 (liquid): 0.30342. Critical temp +9.6°; crit press. 50.7 atm. Flammable. One volume of ethylene gas dissolves in about 4 vols of water at 0°, in about 9 vols of water at 25°, in 0.5 vol alcohol at 25°, in about 0.05 vol ether at 15.5°. Sol in acetone, benzene. Explosive limits (% vol in air), lower: 3.02; upper: 34. Autoignition temp: 1009°F (+543°C). LC for mice in air: 950,000 ppm (Flury).

Caution

Can act as a simple asphyxiant due to oxygen displacement. Exposure to high concns may cause CNS depression, unconsciousness. See Patty's Industrial Hygiene and Toxicology vol. 2B, G. D. Clayton, F. E. Clayton, Eds. (John Wiley & Sons, New York, 4th ed., 1994) p 1241-1244.

Use

Oxyethylene welding and cutting metals; manuf alcohol, mustard gas, and many other organics. Manuf ethylene oxide (for plastics), “Polythene”, polystyrene and other plastics. Plant growth regulator; used commercially to accelerate the ripening of various fruits.

Therapeutic Category

Anesthetic (inhalation).

Therapeutic Category (Veterinary)

Has been used as inhalation anesthetic.

Keywords

Anesthetic (Inhalation)